This invention relates to a method and machine for cleaning sandy beaches which have been contaminated by an oil spill; and more particularly, to the use of liquid nitrogen in such a method and machine.
Ecological damage to beaches from oil spills presents a serious problem to people and water fowl, and it is desirable to restore the beaches to their pre-spill condition as promptly and as efficiently as possible. Heretofore much concentration and effort have been directed toward the solution of handling an oil spill on a water surface, but unfortunately, little effort has been directed toward the handling of the contaminated shoreline.
In the past if the penetration of the oil into the sand was comparatively shallow and the oil was not too fluid the contaminated area has been manually raked into windrows, which were subsequently manually shoveled into a front-end loader or dump truck. If the penetration was comparatively deep, mechanical scrapers and bulldozers have been required to remove the contaminated area. Furthermore, if oil was still washing ashore, a series of deep pits or trenches were dug along the shoreline to catch incoming oil. The oil in the trenches has then been removed by a vacuum tank truck. All of these techniques have been expensive, time-consuming and inefficient.
Another technique for oil removal has been to burn off the oil, but this requires rigid control of the oil fire and the smoke pollutes the atmosphere. Still another prior art method included pouring dispersants and emulsifiers onto the oil spill, but unfortunately, this causes penetration of the oil dispersant/emulsifier mixture into the sand to a depth of at least three times as great as the penetration depth of the untreated oil.
It is, therefore, an object of this invention to provide an efficient and ecologically unharmful method and associated equipment for restoring sandy beaches which have been contaminated by an oil spill.
This and other objects of this invention will become apparent from the following description and appended claims.